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  <title>Document</title>
  <style>
    header,
    footer {
      width: 100%;
      height: 50px;
    }

    header {
      background-color: #000;
      display: -webkit-flex;
      display: -moz-flex;
      display: -o-flx;
      display: -ms-flex;
      display: flex;
    }

    footer {
      background-color: #789;
    }
    .flexbox header{
      display: flex;
      justify-content: center;
      align-items: center;
    }
    .noflex header{
      text-align: center;
      line-height: 50px;
    }
  </style>
</head>

<body>
  <header></header>
  <footer></footer>
  <script>
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      window.webkitRequestAnimationFrame ||
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      function (fn){
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